A169965 Numbers whose decimal expansion contains only 0's and 2's.

0, 2, 20, 22, 200, 202, 220, 222, 2000, 2002, 2020, 2022, 2200, 2202, 2220, 2222, 20000, 20002, 20020, 20022, 20200, 20202, 20220, 20222, 22000, 22002, 22020, 22022, 22200, 22202, 22220, 22222, 200000, 200002, 200020, 200022, 200200, 200202, 200220, 200222

Offset

1,2

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Index entries for sequences related to carryless arithmetic

Formula

a(n+1) = Sum_{k>=0} A030308(n,k)*A093136(k+1). - Philippe Deléham, Oct 16 2011

a(n) = 2 * A007088(n-1).

Mathematica

Map[FromDigits, Tuples[{0, 2}, 6]] (* Paolo Xausa, Oct 30 2023 *)

Prog

(PARI) print1(0); for(d=1, 5, for(n=2^(d-1), 2^d-1, print1(", "); forstep(i=d-1, 0, -1, print1((n>>i)%2*2)))) \\ Charles R Greathouse IV, Nov 16 2011
(Haskell)
a169965 n = a169965_list !! (n-1)
a169965_list = map (* 2) a007088_list
-- Reinhard Zumkeller, Jan 10 2012

Crossrefs

Cf. A007088, A014263, A169964, A169966, A169967.

Cf. A078241, A204093, A204094, A204095, A097256.

Sequence in context: A136885 A359611 A136909 * A202170 A136908 A196748

Adjacent sequences: A169962 A169963 A169964 * A169966 A169967 A169968

Keyword

nonn,base,easy

Author

N. J. A. Sloane, Aug 07 2010

Status

approved